1. Technical Field
The present invention relates to a photoelectric conversion device and electronic equipment provided with the photoelectric conversion device.
2. Related Art
From the past, great attention has been paid to solar cells (photoelectric conversion device) employing silicon as a power source which is harmless to the environment. As for these solar cells employing silicon, a monocrystalline silicon type solar cell is known, which is used in artificial satellites or the like.
In addition, as solar cells for practical applications, there are known a solar cell employing polycrystalline silicon and a solar cell employing amorphous silicon. These solar cells have already been practically used in industrial and household applications.
However, since these solar cells employing silicon require high manufacturing cost and a great deal of energy in manufacturing thereof, these solar cells have not yet reached to a level that can be practically used as an energy-saving power source.
In view of the problem described above, a dye-sensitized solar cell is proposed and developed as a solar cell of the next generation that can be replaced with the above solar cell employing silicon. The dye-sensitized solar cell has advantages that its manufacturing cost is low and it can be manufactured with relatively small energy.
The dye-sensitized solar cell has a structure that includes a transparent electrode, a facing electrode arranged opposite to the transparent electrode, and a semiconductor layer (electron transport layer) carrying a dye and provided between the electrodes.
When the dye-sensitized solar cell receives light, electrons and holes are generated in the dye. And, the electrons and holes are separated with each other on the side of the transparent electrode and the side of the facing electrode, respectively. As a result, a potential difference is created between the transparent electrode and the facing electrode.
For example, Japanese Patent No. 2,664,194 discloses a dye-sensitized solar cell having a semiconductor layer (electron transport layer) constituted of a polycrystalline material of titanium oxide. A dye is adsorbed or carried on surfaces of particles of the polycrystalline material of titanium oxide, and electrons generated in the dye move to an electrode through the particles.
However, there is a problem in that the polycrystalline material of titanium oxide do not have a sufficient electron transport ability which transfers electrons from the dye to the electrode.